1 // SPDX-License-Identifier: GPL-2.0
26  * struct psz_buffer - header of zone to flush to storage
28  * @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value)
42  * struct psz_kmsg_header - kmsg dump-specific header to flush to storage
44  * @magic: magic num for kmsg dump header
45  * @time: kmsg dump trigger time
47  * @counter: kmsg dump counter
48  * @reason: the kmsg dump reason (e.g. oops, panic, etc)
51  * This is a sub-header for a kmsg dump, trailing after &psz_buffer.
64  * struct pstore_zone - single stored buffer
67  * @type: front-end type for this zone
68  * @name: front-end name for this zone
71  * @buffer_size: bytes in @buffer->data
90  * struct psz_context - all about running state of pstore/zone
92  * @kpszs: kmsg dump storage zones
98  * @kmsg_write_cnt: counter of total kmsg dump writes
103  * @oops_counter: counter of oops dumps
125 	 * It records the oops/panic times after crashes rather than boots.
146  * enum psz_flush_mode - flush mode for psz_zone_write()
162 	return atomic_read(&zone->buffer->datalen);  in buffer_datalen()
167 	return atomic_read(&zone->buffer->start);  in buffer_start()
178 	if (!buf || !zone || !zone->buffer)  in psz_zone_read_buffer()
179 		return -EINVAL;  in psz_zone_read_buffer()
180 	if (off > zone->buffer_size)  in psz_zone_read_buffer()
181 		return -EINVAL;  in psz_zone_read_buffer()
182 	len = min_t(size_t, len, zone->buffer_size - off);  in psz_zone_read_buffer()
183 	memcpy(buf, zone->buffer->data + off, len);  in psz_zone_read_buffer()
190 	if (!buf || !zone || !zone->oldbuf)  in psz_zone_read_oldbuf()
191 		return -EINVAL;  in psz_zone_read_oldbuf()
192 	if (off > zone->buffer_size)  in psz_zone_read_oldbuf()
193 		return -EINVAL;  in psz_zone_read_oldbuf()
194 	len = min_t(size_t, len, zone->buffer_size - off);  in psz_zone_read_oldbuf()
195 	memcpy(buf, zone->oldbuf->data + off, len);  in psz_zone_read_oldbuf()
208 	if (off > zone->buffer_size)  in psz_zone_write()
209 		return -EINVAL;  in psz_zone_write()
211 	wlen = min_t(size_t, len, zone->buffer_size - off);  in psz_zone_write()
213 		memcpy(zone->buffer->data + off, buf, wlen);  in psz_zone_write()
214 		atomic_set(&zone->buffer->datalen, wlen + off);  in psz_zone_write()
221 	writeop = is_on_panic() ? info->panic_write : info->write;  in psz_zone_write()
231 		wcnt = writeop((const char *)zone->buffer->data + off, wlen,  in psz_zone_write()
232 				zone->off + sizeof(*zone->buffer) + off);  in psz_zone_write()
238 		wcnt = writeop((const char *)zone->buffer, wlen, zone->off);  in psz_zone_write()
243 		wlen = zone->buffer_size + sizeof(*zone->buffer);  in psz_zone_write()
244 		wcnt = writeop((const char *)zone->buffer, wlen, zone->off);  in psz_zone_write()
252 	/* no need to mark dirty if going to try next zone */  in psz_zone_write()
253 	if (wcnt == -ENOMSG)  in psz_zone_write()
254 		return -ENOMSG;  in psz_zone_write()
255 	atomic_set(&zone->dirty, true);  in psz_zone_write()
257 	if (wcnt == -EBUSY && !is_on_panic())  in psz_zone_write()
259 	return -EBUSY;  in psz_zone_write()
267 		return -EINVAL;  in psz_flush_dirty_zone()
270 		return -EBUSY;  in psz_flush_dirty_zone()
272 	if (!atomic_xchg(&zone->dirty, false))  in psz_flush_dirty_zone()
277 		atomic_set(&zone->dirty, true);  in psz_flush_dirty_zone()
287 		return -EINVAL;  in psz_flush_dirty_zones()
292 			return -EINVAL;  in psz_flush_dirty_zones()
302 	const char *data = (const char *)old->buffer->data;  in psz_move_zone()
307 		atomic_set(&new->buffer->datalen, 0);  in psz_move_zone()
308 		atomic_set(&new->dirty, false);  in psz_move_zone()
311 	atomic_set(&old->buffer->datalen, 0);  in psz_move_zone()
320 	if (cxt->ppsz)  in psz_flush_all_dirty_zones()
321 		ret |= psz_flush_dirty_zone(cxt->ppsz);  in psz_flush_all_dirty_zones()
322 	if (cxt->cpsz)  in psz_flush_all_dirty_zones()
323 		ret |= psz_flush_dirty_zone(cxt->cpsz);  in psz_flush_all_dirty_zones()
324 	if (cxt->kpszs)  in psz_flush_all_dirty_zones()
325 		ret |= psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt);  in psz_flush_all_dirty_zones()
326 	if (cxt->fpszs)  in psz_flush_all_dirty_zones()
327 		ret |= psz_flush_dirty_zones(cxt->fpszs, cxt->ftrace_max_cnt);  in psz_flush_all_dirty_zones()
328 	if (ret && cxt->pstore_zone_info)  in psz_flush_all_dirty_zones()
334 	struct pstore_zone_info *info = cxt->pstore_zone_info;  in psz_kmsg_recover_data()
340 	if (!info->read)  in psz_kmsg_recover_data()
341 		return -EINVAL;  in psz_kmsg_recover_data()
343 	for (i = 0; i < cxt->kmsg_max_cnt; i++) {  in psz_kmsg_recover_data()
344 		zone = cxt->kpszs[i];  in psz_kmsg_recover_data()
346 			return -EINVAL;  in psz_kmsg_recover_data()
347 		if (atomic_read(&zone->dirty)) {  in psz_kmsg_recover_data()
348 			unsigned int wcnt = cxt->kmsg_write_cnt;  in psz_kmsg_recover_data()
349 			struct pstore_zone *new = cxt->kpszs[wcnt];  in psz_kmsg_recover_data()
358 			cxt->kmsg_write_cnt = (wcnt + 1) % cxt->kmsg_max_cnt;  in psz_kmsg_recover_data()
360 		if (!zone->should_recover)  in psz_kmsg_recover_data()
362 		buf = zone->buffer;  in psz_kmsg_recover_data()
363 		rcnt = info->read((char *)buf, zone->buffer_size + sizeof(*buf),  in psz_kmsg_recover_data()
364 				zone->off);  in psz_kmsg_recover_data()
365 		if (rcnt != zone->buffer_size + sizeof(*buf))  in psz_kmsg_recover_data()
366 			return rcnt < 0 ? rcnt : -EIO;  in psz_kmsg_recover_data()
373 	struct pstore_zone_info *info = cxt->pstore_zone_info;  in psz_kmsg_recover_meta()
386 	if (!info->read)  in psz_kmsg_recover_meta()
387 		return -EINVAL;  in psz_kmsg_recover_meta()
391 	for (i = 0; i < cxt->kmsg_max_cnt; i++) {  in psz_kmsg_recover_meta()
392 		zone = cxt->kpszs[i];  in psz_kmsg_recover_meta()
394 			return -EINVAL;  in psz_kmsg_recover_meta()
396 		rcnt = info->read((char *)buf, len, zone->off);  in psz_kmsg_recover_meta()
397 		if (rcnt == -ENOMSG) {  in psz_kmsg_recover_meta()
399 					zone->name, i);  in psz_kmsg_recover_meta()
402 			pr_err("read %s with id %lu failed\n", zone->name, i);  in psz_kmsg_recover_meta()
403 			return rcnt < 0 ? rcnt : -EIO;  in psz_kmsg_recover_meta()
406 		if (buf->sig != zone->buffer->sig) {  in psz_kmsg_recover_meta()
407 			pr_debug("no valid data in kmsg dump zone %lu\n", i);  in psz_kmsg_recover_meta()
411 		if (zone->buffer_size < atomic_read(&buf->datalen)) {  in psz_kmsg_recover_meta()
413 					zone->name, i, zone->off,  in psz_kmsg_recover_meta()
414 					zone->buffer_size);  in psz_kmsg_recover_meta()
418 		hdr = (struct psz_kmsg_header *)buf->data;  in psz_kmsg_recover_meta()
419 		if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) {  in psz_kmsg_recover_meta()
421 					zone->name, i, zone->off,  in psz_kmsg_recover_meta()
422 					zone->buffer_size);  in psz_kmsg_recover_meta()
430 		if (hdr->time.tv_sec >= time.tv_sec) {  in psz_kmsg_recover_meta()
431 			time.tv_sec = hdr->time.tv_sec;  in psz_kmsg_recover_meta()
432 			cxt->kmsg_write_cnt = (i + 1) % cxt->kmsg_max_cnt;  in psz_kmsg_recover_meta()
435 		if (hdr->reason == KMSG_DUMP_OOPS)  in psz_kmsg_recover_meta()
436 			cxt->oops_counter =  in psz_kmsg_recover_meta()
437 				max(cxt->oops_counter, hdr->counter);  in psz_kmsg_recover_meta()
438 		else if (hdr->reason == KMSG_DUMP_PANIC)  in psz_kmsg_recover_meta()
439 			cxt->panic_counter =  in psz_kmsg_recover_meta()
440 				max(cxt->panic_counter, hdr->counter);  in psz_kmsg_recover_meta()
442 		if (!atomic_read(&buf->datalen)) {  in psz_kmsg_recover_meta()
444 					zone->name, i, zone->off,  in psz_kmsg_recover_meta()
445 					zone->buffer_size,  in psz_kmsg_recover_meta()
446 					atomic_read(&buf->datalen));  in psz_kmsg_recover_meta()
451 			zone->should_recover = true;  in psz_kmsg_recover_meta()
453 				zone->name, i, zone->off,  in psz_kmsg_recover_meta()
454 				zone->buffer_size, atomic_read(&buf->datalen));  in psz_kmsg_recover_meta()
464 	if (!cxt->kpszs)  in psz_kmsg_recover()
483 	struct pstore_zone_info *info = cxt->pstore_zone_info;  in psz_recover_zone()
489 	if (!zone || zone->oldbuf)  in psz_recover_zone()
498 	if (unlikely(!info->read))  in psz_recover_zone()
499 		return -EINVAL;  in psz_recover_zone()
502 	rcnt = info->read((char *)&tmpbuf, len, zone->off);  in psz_recover_zone()
504 		pr_debug("read zone %s failed\n", zone->name);  in psz_recover_zone()
505 		return rcnt < 0 ? rcnt : -EIO;  in psz_recover_zone()
508 	if (tmpbuf.sig != zone->buffer->sig) {  in psz_recover_zone()
509 		pr_debug("no valid data in zone %s\n", zone->name);  in psz_recover_zone()
513 	if (zone->buffer_size < atomic_read(&tmpbuf.datalen) ||  in psz_recover_zone()
514 		zone->buffer_size < atomic_read(&tmpbuf.start)) {  in psz_recover_zone()
516 				zone->name, zone->off, zone->buffer_size);  in psz_recover_zone()
523 				zone->name, zone->off, zone->buffer_size,  in psz_recover_zone()
529 			zone->name, zone->off, zone->buffer_size,  in psz_recover_zone()
535 		return -ENOMEM;  in psz_recover_zone()
539 	len = atomic_read(&oldbuf->datalen);  in psz_recover_zone()
540 	start = atomic_read(&oldbuf->start);  in psz_recover_zone()
541 	off = zone->off + sizeof(*oldbuf);  in psz_recover_zone()
544 	rcnt = info->read(buf, len - start, off + start);  in psz_recover_zone()
545 	if (rcnt != len - start) {  in psz_recover_zone()
546 		pr_err("read zone %s failed\n", zone->name);  in psz_recover_zone()
547 		ret = rcnt < 0 ? rcnt : -EIO;  in psz_recover_zone()
552 	rcnt = info->read(buf + len - start, start, off);  in psz_recover_zone()
554 		pr_err("read zone %s failed\n", zone->name);  in psz_recover_zone()
555 		ret = rcnt < 0 ? rcnt : -EIO;  in psz_recover_zone()
559 	zone->oldbuf = oldbuf;  in psz_recover_zone()
589 	pr_debug("recover %s[%u] failed\n", zone->name, i);  in psz_recover_zones()
594  * psz_recovery() - recover data from storage
605 	if (atomic_read(&cxt->recovered))  in psz_recovery()
612 	ret = psz_recover_zone(cxt, cxt->ppsz);  in psz_recovery()
616 	ret = psz_recover_zone(cxt, cxt->cpsz);  in psz_recovery()
620 	ret = psz_recover_zones(cxt, cxt->fpszs, cxt->ftrace_max_cnt);  in psz_recovery()
627 		atomic_set(&cxt->recovered, 1);  in psz_recovery()
634 	struct psz_context *cxt = psi->data;  in psz_pstore_open()
636 	cxt->kmsg_read_cnt = 0;  in psz_pstore_open()
637 	cxt->pmsg_read_cnt = 0;  in psz_pstore_open()
638 	cxt->console_read_cnt = 0;  in psz_pstore_open()
639 	cxt->ftrace_read_cnt = 0;  in psz_pstore_open()
645 	if (zone && zone->oldbuf && atomic_read(&zone->oldbuf->datalen))  in psz_old_ok()
652 	if (zone && zone->buffer && buffer_datalen(zone))  in psz_ok()
660 	struct psz_buffer *buffer = zone->buffer;  in psz_kmsg_erase()
662 		(struct psz_kmsg_header *)buffer->data;  in psz_kmsg_erase()
668 	/* this zone is already updated, no need to erase */  in psz_kmsg_erase()
669 	if (record->count != hdr->counter)  in psz_kmsg_erase()
672 	size = buffer_datalen(zone) + sizeof(*zone->buffer);  in psz_kmsg_erase()
673 	atomic_set(&zone->buffer->datalen, 0);  in psz_kmsg_erase()
674 	if (cxt->pstore_zone_info->erase)  in psz_kmsg_erase()
675 		return cxt->pstore_zone_info->erase(size, zone->off);  in psz_kmsg_erase()
686 	kfree(zone->oldbuf);  in psz_record_erase()
687 	zone->oldbuf = NULL;  in psz_record_erase()
690 	 * are already invalid. It is no need to flush 0 (erase) to  in psz_record_erase()
701 	struct psz_context *cxt = record->psi->data;  in psz_pstore_erase()
703 	switch (record->type) {  in psz_pstore_erase()
705 		if (record->id >= cxt->kmsg_max_cnt)  in psz_pstore_erase()
706 			return -EINVAL;  in psz_pstore_erase()
707 		return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record);  in psz_pstore_erase()
709 		return psz_record_erase(cxt, cxt->ppsz);  in psz_pstore_erase()
711 		return psz_record_erase(cxt, cxt->cpsz);  in psz_pstore_erase()
713 		if (record->id >= cxt->ftrace_max_cnt)  in psz_pstore_erase()
714 			return -EINVAL;  in psz_pstore_erase()
715 		return psz_record_erase(cxt, cxt->fpszs[record->id]);  in psz_pstore_erase()
716 	default: return -EINVAL;  in psz_pstore_erase()
723 	struct psz_context *cxt = record->psi->data;  in psz_write_kmsg_hdr()
724 	struct psz_buffer *buffer = zone->buffer;  in psz_write_kmsg_hdr()
726 		(struct psz_kmsg_header *)buffer->data;  in psz_write_kmsg_hdr()
728 	hdr->magic = PSTORE_KMSG_HEADER_MAGIC;  in psz_write_kmsg_hdr()
729 	hdr->compressed = record->compressed;  in psz_write_kmsg_hdr()
730 	hdr->time.tv_sec = record->time.tv_sec;  in psz_write_kmsg_hdr()
731 	hdr->time.tv_nsec = record->time.tv_nsec;  in psz_write_kmsg_hdr()
732 	hdr->reason = record->reason;  in psz_write_kmsg_hdr()
733 	if (hdr->reason == KMSG_DUMP_OOPS)  in psz_write_kmsg_hdr()
734 		hdr->counter = ++cxt->oops_counter;  in psz_write_kmsg_hdr()
735 	else if (hdr->reason == KMSG_DUMP_PANIC)  in psz_write_kmsg_hdr()
736 		hdr->counter = ++cxt->panic_counter;  in psz_write_kmsg_hdr()
738 		hdr->counter = 0;  in psz_write_kmsg_hdr()
743  * start at cxt->kmsg_write_cnt.
752 	for (i = 0; i < cxt->kmsg_max_cnt; i++) {  in psz_kmsg_write_record()
756 		zonenum = (cxt->kmsg_write_cnt + i) % cxt->kmsg_max_cnt;  in psz_kmsg_write_record()
757 		zone = cxt->kpszs[zonenum];  in psz_kmsg_write_record()
759 			return -ENOSPC;  in psz_kmsg_write_record()
762 		len = zone->buffer_size + sizeof(*zone->buffer);  in psz_kmsg_write_record()
763 		zone->oldbuf = zone->buffer;  in psz_kmsg_write_record()
764 		zone->buffer = kzalloc(len, GFP_ATOMIC);  in psz_kmsg_write_record()
765 		if (!zone->buffer) {  in psz_kmsg_write_record()
766 			zone->buffer = zone->oldbuf;  in psz_kmsg_write_record()
767 			return -ENOMEM;  in psz_kmsg_write_record()
769 		zone->buffer->sig = zone->oldbuf->sig;  in psz_kmsg_write_record()
771 		pr_debug("write %s to zone id %d\n", zone->name, zonenum);  in psz_kmsg_write_record()
774 		size = min_t(size_t, record->size, zone->buffer_size - hlen);  in psz_kmsg_write_record()
775 		ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen);  in psz_kmsg_write_record()
776 		if (likely(!ret || ret != -ENOMSG)) {  in psz_kmsg_write_record()
777 			cxt->kmsg_write_cnt = zonenum + 1;  in psz_kmsg_write_record()
778 			cxt->kmsg_write_cnt %= cxt->kmsg_max_cnt;  in psz_kmsg_write_record()
779 			/* no need to try next zone, free last zone buffer */  in psz_kmsg_write_record()
780 			kfree(zone->oldbuf);  in psz_kmsg_write_record()
781 			zone->oldbuf = NULL;  in psz_kmsg_write_record()
787 		kfree(zone->buffer);  in psz_kmsg_write_record()
788 		zone->buffer = zone->oldbuf;  in psz_kmsg_write_record()
789 		zone->oldbuf = NULL;  in psz_kmsg_write_record()
792 	return -EBUSY;  in psz_kmsg_write_record()
806 	if (record->part != 1)  in psz_kmsg_write()
807 		return -ENOSPC;  in psz_kmsg_write()
809 	if (!cxt->kpszs)  in psz_kmsg_write()
810 		return -ENOSPC;  in psz_kmsg_write()
832 		return -ENOSPC;  in psz_record_write()
834 	if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size)  in psz_record_write()
837 	cnt = record->size;  in psz_record_write()
838 	buf = record->buf;  in psz_record_write()
839 	if (unlikely(cnt > zone->buffer_size)) {  in psz_record_write()
840 		buf += cnt - zone->buffer_size;  in psz_record_write()
841 		cnt = zone->buffer_size;  in psz_record_write()
845 	rem = zone->buffer_size - start;  in psz_record_write()
849 		cnt -= rem;  in psz_record_write()
854 	atomic_set(&zone->buffer->start, cnt + start);  in psz_record_write()
861 	 * beginning of zone, which make buffer->datalen wrongly.  in psz_record_write()
866 		atomic_set(&zone->buffer->datalen, zone->buffer_size);  in psz_record_write()
874 	struct psz_context *cxt = record->psi->data;  in psz_pstore_write()
876 	if (record->type == PSTORE_TYPE_DMESG &&  in psz_pstore_write()
877 			record->reason == KMSG_DUMP_PANIC)  in psz_pstore_write()
878 		atomic_set(&cxt->on_panic, 1);  in psz_pstore_write()
884 	if (is_on_panic() && record->type != PSTORE_TYPE_DMESG)  in psz_pstore_write()
885 		return -EBUSY;  in psz_pstore_write()
887 	switch (record->type) {  in psz_pstore_write()
891 		return psz_record_write(cxt->cpsz, record);  in psz_pstore_write()
893 		return psz_record_write(cxt->ppsz, record);  in psz_pstore_write()
897 		if (!cxt->fpszs)  in psz_pstore_write()
898 			return -ENOSPC;  in psz_pstore_write()
899 		return psz_record_write(cxt->fpszs[zonenum], record);  in psz_pstore_write()
902 		return -EINVAL;  in psz_pstore_write()
910 	while (cxt->kmsg_read_cnt < cxt->kmsg_max_cnt) {  in psz_read_next_zone()
911 		zone = cxt->kpszs[cxt->kmsg_read_cnt++];  in psz_read_next_zone()
916 	if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt)  in psz_read_next_zone()
918 		 * No need psz_old_ok(). Let psz_ftrace_read() do so for  in psz_read_next_zone()
922 		return cxt->fpszs[cxt->ftrace_read_cnt++];  in psz_read_next_zone()
924 	if (cxt->pmsg_read_cnt == 0) {  in psz_read_next_zone()
925 		cxt->pmsg_read_cnt++;  in psz_read_next_zone()
926 		zone = cxt->ppsz;  in psz_read_next_zone()
931 	if (cxt->console_read_cnt == 0) {  in psz_read_next_zone()
932 		cxt->console_read_cnt++;  in psz_read_next_zone()
933 		zone = cxt->cpsz;  in psz_read_next_zone()
944 	struct psz_buffer *buffer = zone->buffer;  in psz_kmsg_read_hdr()
946 		(struct psz_kmsg_header *)buffer->data;  in psz_kmsg_read_hdr()
948 	if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC)  in psz_kmsg_read_hdr()
949 		return -EINVAL;  in psz_kmsg_read_hdr()
950 	record->compressed = hdr->compressed;  in psz_kmsg_read_hdr()
951 	record->time.tv_sec = hdr->time.tv_sec;  in psz_kmsg_read_hdr()
952 	record->time.tv_nsec = hdr->time.tv_nsec;  in psz_kmsg_read_hdr()
953 	record->reason = hdr->reason;  in psz_kmsg_read_hdr()
954 	record->count = hdr->counter;  in psz_kmsg_read_hdr()
964 	/* Clear and skip this kmsg dump record if it has no valid header */  in psz_kmsg_read()
966 		atomic_set(&zone->buffer->datalen, 0);  in psz_kmsg_read()
967 		atomic_set(&zone->dirty, 0);  in psz_kmsg_read()
968 		return -ENOMSG;  in psz_kmsg_read()
970 	size -= sizeof(struct psz_kmsg_header);  in psz_kmsg_read()
972 	if (!record->compressed) {  in psz_kmsg_read()
974 				      kmsg_dump_reason_str(record->reason),  in psz_kmsg_read()
975 				      record->count);  in psz_kmsg_read()
977 			return -ENOMEM;  in psz_kmsg_read()
979 		record->buf = krealloc(buf, hlen + size, GFP_KERNEL);  in psz_kmsg_read()
980 		if (!record->buf) {  in psz_kmsg_read()
982 			return -ENOMEM;  in psz_kmsg_read()
985 		record->buf = kmalloc(size, GFP_KERNEL);  in psz_kmsg_read()
986 		if (!record->buf)  in psz_kmsg_read()
987 			return -ENOMEM;  in psz_kmsg_read()
990 	size = psz_zone_read_buffer(zone, record->buf + hlen, size,  in psz_kmsg_read()
993 		kfree(record->buf);  in psz_kmsg_read()
994 		return -ENOMSG;  in psz_kmsg_read()
1009 		return -ENOSPC;  in psz_ftrace_read()
1014 	buf = (struct psz_buffer *)zone->oldbuf;  in psz_ftrace_read()
1016 		return -ENOMSG;  in psz_ftrace_read()
1018 	ret = pstore_ftrace_combine_log(&record->buf, &record->size,  in psz_ftrace_read()
1019 			(char *)buf->data, atomic_read(&buf->datalen));  in psz_ftrace_read()
1024 	cxt = record->psi->data;  in psz_ftrace_read()
1025 	if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt)  in psz_ftrace_read()
1027 		return -ENOMSG;  in psz_ftrace_read()
1028 	record->id = 0;  in psz_ftrace_read()
1029 	return record->size ? record->size : -ENOMSG;  in psz_ftrace_read()
1039 		return -ENOSPC;  in psz_record_read()
1041 	buf = (struct psz_buffer *)zone->oldbuf;  in psz_record_read()
1043 		return -ENOMSG;  in psz_record_read()
1045 	len = atomic_read(&buf->datalen);  in psz_record_read()
1046 	record->buf = kmalloc(len, GFP_KERNEL);  in psz_record_read()
1047 	if (!record->buf)  in psz_record_read()
1048 		return -ENOMEM;  in psz_record_read()
1050 	if (unlikely(psz_zone_read_oldbuf(zone, record->buf, len, 0))) {  in psz_record_read()
1051 		kfree(record->buf);  in psz_record_read()
1052 		return -ENOMSG;  in psz_record_read()
1060 	struct psz_context *cxt = record->psi->data;  in psz_pstore_read()
1076 	record->type = zone->type;  in psz_pstore_read()
1077 	switch (record->type) {  in psz_pstore_read()
1080 		record->id = cxt->kmsg_read_cnt - 1;  in psz_pstore_read()
1094 	if (ret == -ENOMSG)  in psz_pstore_read()
1120 	kfree(zone->buffer);  in psz_free_zone()
1133 		(*cnt)--;  in psz_free_zones()
1142 	if (cxt->kpszs)  in psz_free_all_zones()
1143 		psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt);  in psz_free_all_zones()
1144 	if (cxt->ppsz)  in psz_free_all_zones()
1145 		psz_free_zone(&cxt->ppsz);  in psz_free_all_zones()
1146 	if (cxt->cpsz)  in psz_free_all_zones()
1147 		psz_free_zone(&cxt->cpsz);  in psz_free_all_zones()
1148 	if (cxt->fpszs)  in psz_free_all_zones()
1149 		psz_free_zones(&cxt->fpszs, &cxt->ftrace_max_cnt);  in psz_free_all_zones()
1162 	if (*off + size > info->total_size) {  in psz_init_zone()
1163 		pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n",  in psz_init_zone()
1164 			name, size, *off, info->total_size);  in psz_init_zone()
1165 		return ERR_PTR(-ENOMEM);  in psz_init_zone()
1170 		return ERR_PTR(-ENOMEM);  in psz_init_zone()
1172 	zone->buffer = kmalloc(size, GFP_KERNEL);  in psz_init_zone()
1173 	if (!zone->buffer) {  in psz_init_zone()
1175 		return ERR_PTR(-ENOMEM);  in psz_init_zone()
1177 	memset(zone->buffer, 0xFF, size);  in psz_init_zone()
1178 	zone->off = *off;  in psz_init_zone()
1179 	zone->name = name;  in psz_init_zone()
1180 	zone->type = type;  in psz_init_zone()
1181 	zone->buffer_size = size - sizeof(struct psz_buffer);  in psz_init_zone()
1182 	zone->buffer->sig = type ^ PSZ_SIG;  in psz_init_zone()
1183 	zone->oldbuf = NULL;  in psz_init_zone()
1184 	atomic_set(&zone->dirty, 0);  in psz_init_zone()
1185 	atomic_set(&zone->buffer->datalen, 0);  in psz_init_zone()
1186 	atomic_set(&zone->buffer->start, 0);  in psz_init_zone()
1190 	pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name,  in psz_init_zone()
1191 			zone->off, sizeof(*zone->buffer), zone->buffer_size);  in psz_init_zone()
1208 	if (*off + total_size > info->total_size) {  in psz_init_zones()
1209 		pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n",  in psz_init_zones()
1210 			name, total_size, *off, info->total_size);  in psz_init_zones()
1211 		return ERR_PTR(-ENOMEM);  in psz_init_zones()
1218 		return ERR_PTR(-ENOMEM);  in psz_init_zones()
1237 	struct pstore_zone_info *info = cxt->pstore_zone_info;  in psz_alloc_zones()
1242 	off_size += info->pmsg_size;  in psz_alloc_zones()
1243 	cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size);  in psz_alloc_zones()
1244 	if (IS_ERR(cxt->ppsz)) {  in psz_alloc_zones()
1245 		err = PTR_ERR(cxt->ppsz);  in psz_alloc_zones()
1246 		cxt->ppsz = NULL;  in psz_alloc_zones()
1250 	off_size += info->console_size;  in psz_alloc_zones()
1251 	cxt->cpsz = psz_init_zone(PSTORE_TYPE_CONSOLE, &off,  in psz_alloc_zones()
1252 			info->console_size);  in psz_alloc_zones()
1253 	if (IS_ERR(cxt->cpsz)) {  in psz_alloc_zones()
1254 		err = PTR_ERR(cxt->cpsz);  in psz_alloc_zones()
1255 		cxt->cpsz = NULL;  in psz_alloc_zones()
1259 	off_size += info->ftrace_size;  in psz_alloc_zones()
1260 	cxt->fpszs = psz_init_zones(PSTORE_TYPE_FTRACE, &off,  in psz_alloc_zones()
1261 			info->ftrace_size,  in psz_alloc_zones()
1262 			info->ftrace_size / nr_cpu_ids,  in psz_alloc_zones()
1263 			&cxt->ftrace_max_cnt);  in psz_alloc_zones()
1264 	if (IS_ERR(cxt->fpszs)) {  in psz_alloc_zones()
1265 		err = PTR_ERR(cxt->fpszs);  in psz_alloc_zones()
1266 		cxt->fpszs = NULL;  in psz_alloc_zones()
1270 	cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off,  in psz_alloc_zones()
1271 			info->total_size - off_size,  in psz_alloc_zones()
1272 			info->kmsg_size, &cxt->kmsg_max_cnt);  in psz_alloc_zones()
1273 	if (IS_ERR(cxt->kpszs)) {  in psz_alloc_zones()
1274 		err = PTR_ERR(cxt->kpszs);  in psz_alloc_zones()
1275 		cxt->kpszs = NULL;  in psz_alloc_zones()
1286  * register_pstore_zone() - register to pstore/zone
1288  * @info: back-end driver information. See &struct pstore_zone_info.
1290  * Only one back-end at one time.
1296 	int err = -EINVAL;  in register_pstore_zone()
1299 	if (info->total_size < 4096) {  in register_pstore_zone()
1301 		return -EINVAL;  in register_pstore_zone()
1303 	if (info->total_size > SZ_128M) {  in register_pstore_zone()
1305 		info->total_size = SZ_128M;  in register_pstore_zone()
1308 	if (!info->kmsg_size && !info->pmsg_size && !info->console_size &&  in register_pstore_zone()
1309 	    !info->ftrace_size) {  in register_pstore_zone()
1310 		pr_warn("at least one record size must be non-zero\n");  in register_pstore_zone()
1311 		return -EINVAL;  in register_pstore_zone()
1314 	if (!info->name || !info->name[0])  in register_pstore_zone()
1315 		return -EINVAL;  in register_pstore_zone()
1318 		if (info->name > 0 && info->name < (size)) {		\  in register_pstore_zone()
1320 			return -EINVAL;					\  in register_pstore_zone()
1322 		if (info->name & (size - 1)) {				\  in register_pstore_zone()
1325 			return -EINVAL;					\  in register_pstore_zone()
1339 	 * if no @read, pstore may mount failed.  in register_pstore_zone()
1340 	 * if no @write, pstore do not support to remove record file.  in register_pstore_zone()
1342 	if (!info->read || !info->write) {  in register_pstore_zone()
1343 		pr_err("no valid general read/write interface\n");  in register_pstore_zone()
1344 		return -EINVAL;  in register_pstore_zone()
1347 	mutex_lock(&cxt->pstore_zone_info_lock);  in register_pstore_zone()
1348 	if (cxt->pstore_zone_info) {  in register_pstore_zone()
1350 				cxt->pstore_zone_info->name, info->name);  in register_pstore_zone()
1351 		mutex_unlock(&cxt->pstore_zone_info_lock);  in register_pstore_zone()
1352 		return -EBUSY;  in register_pstore_zone()
1354 	cxt->pstore_zone_info = info;  in register_pstore_zone()
1356 	pr_debug("register %s with properties:\n", info->name);  in register_pstore_zone()
1357 	pr_debug("\ttotal size : %ld Bytes\n", info->total_size);  in register_pstore_zone()
1358 	pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size);  in register_pstore_zone()
1359 	pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size);  in register_pstore_zone()
1360 	pr_debug("\tconsole size : %ld Bytes\n", info->console_size);  in register_pstore_zone()
1361 	pr_debug("\tftrace size : %ld Bytes\n", info->ftrace_size);  in register_pstore_zone()
1369 	if (info->kmsg_size) {  in register_pstore_zone()
1370 		cxt->pstore.bufsize = cxt->kpszs[0]->buffer_size -  in register_pstore_zone()
1372 		cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);  in register_pstore_zone()
1373 		if (!cxt->pstore.buf) {  in register_pstore_zone()
1374 			err = -ENOMEM;  in register_pstore_zone()
1378 	cxt->pstore.data = cxt;  in register_pstore_zone()
1380 	pr_info("registered %s as backend for", info->name);  in register_pstore_zone()
1381 	cxt->pstore.max_reason = info->max_reason;  in register_pstore_zone()
1382 	cxt->pstore.name = info->name;  in register_pstore_zone()
1383 	if (info->kmsg_size) {  in register_pstore_zone()
1384 		cxt->pstore.flags |= PSTORE_FLAGS_DMESG;  in register_pstore_zone()
1386 			kmsg_dump_reason_str(cxt->pstore.max_reason));  in register_pstore_zone()
1387 		if (cxt->pstore_zone_info->panic_write)  in register_pstore_zone()
1391 	if (info->pmsg_size) {  in register_pstore_zone()
1392 		cxt->pstore.flags |= PSTORE_FLAGS_PMSG;  in register_pstore_zone()
1395 	if (info->console_size) {  in register_pstore_zone()
1396 		cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;  in register_pstore_zone()
1399 	if (info->ftrace_size) {  in register_pstore_zone()
1400 		cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;  in register_pstore_zone()
1405 	err = pstore_register(&cxt->pstore);  in register_pstore_zone()
1415 	kfree(cxt->pstore.buf);  in register_pstore_zone()
1416 	cxt->pstore.buf = NULL;  in register_pstore_zone()
1417 	cxt->pstore.bufsize = 0;  in register_pstore_zone()
1427  * unregister_pstore_zone() - unregister to pstore/zone
1429  * @info: back-end driver information. See struct pstore_zone_info.
1435 	mutex_lock(&cxt->pstore_zone_info_lock);  in unregister_pstore_zone()
1436 	if (!cxt->pstore_zone_info) {  in unregister_pstore_zone()
1437 		mutex_unlock(&cxt->pstore_zone_info_lock);  in unregister_pstore_zone()
1442 	pstore_unregister(&cxt->pstore);  in unregister_pstore_zone()
1449 	kfree(cxt->pstore.buf);  in unregister_pstore_zone()
1450 	cxt->pstore.buf = NULL;  in unregister_pstore_zone()
1451 	cxt->pstore.bufsize = 0;  in unregister_pstore_zone()
1452 	cxt->pstore_zone_info = NULL;  in unregister_pstore_zone()
1457 	cxt->oops_counter = 0;  in unregister_pstore_zone()
1458 	cxt->panic_counter = 0;  in unregister_pstore_zone()
1459 	atomic_set(&cxt->recovered, 0);  in unregister_pstore_zone()
1460 	atomic_set(&cxt->on_panic, 0);  in unregister_pstore_zone()
1462 	mutex_unlock(&cxt->pstore_zone_info_lock);  in unregister_pstore_zone()